Qualify library names in packages

lib/src/compiler/code_generator.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:collection' show HashMap, HashSet;
 
 import 'package:analyzer/analyzer.dart' hide ConstantEvaluator;
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart' show Token, TokenType;
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 95 matching lines @@
 
   /// The current function body being compiled.
   FunctionBody _currentFunction;
 
   /// Helper class for emitting elements in the proper order to allow
   /// JS to load the module.
   ElementLoader _loader;
 
   BuildUnit _buildUnit;
 
+  String _buildRoot;
+
   CodeGenerator(AnalysisContext c, this.options, this._extensionTypes)
       : context = c,
         types = c.typeProvider,
         _asyncStreamIterator =
             _getLibrary(c, 'dart:async').getType('StreamIterator').type,
         _jsArray = _getLibrary(c, 'dart:_interceptors').getType('JSArray'),
         dartCoreLibrary = _getLibrary(c, 'dart:core'),
         dartJSLibrary = _getLibrary(c, 'dart:js');
 
   LibraryElement get currentLibrary => _loader.currentElement.library;
 
   /// The main entry point to JavaScript code generation.
   ///
   /// Takes the metadata for the build unit, as well as resolved trees and
   /// errors, and computes the output module code and optionally the source map.
   JSModuleFile compile(BuildUnit unit, List<CompilationUnit> compilationUnits,
       List<String> errors) {
     _buildUnit = unit;
+    _buildRoot = _buildUnit.buildRoot;
+    if (!_buildRoot.endsWith('/')) {

[Paul Berry, 2016/04/28 15:49:30]

AFAICT, buildRoot uses OS conventions, this won't work on Windows.  Use
`path.separator` (here and in the line below).

[vsm, 2016/04/28 21:18:04]

Hmm, buildRoot might not actually be a native file path (though it is by
default).  jakemac passes in some sort of assert uri.

Perhaps this should be a Uri?

+      _buildRoot = '$_buildRoot/';
+    }
 
     var jsTree = _emitModule(compilationUnits);
     var codeAndSourceMap = _writeJSText(unit, jsTree);
 
     List<int> summary;
     if (options.summarizeApi) {
       var assembler = new PackageBundleAssembler();
       compilationUnits
           .map((u) => u.element.library)
           .toSet()
@@ skipping 39 matching lines @@
     compilationUnits = CoercionReifier.reify(compilationUnits);
 
     // Initialize our library variables.
     var items = <JS.ModuleItem>[];
     for (var unit in compilationUnits) {
       var library = unit.element.library;
       if (unit.element != library.definingCompilationUnit) continue;
 
       var libraryTemp = _isDartRuntime(library)
           ? _runtimeLibVar
-          : new JS.TemporaryId(jsLibraryName(library));
+          : new JS.TemporaryId(jsLibraryName(_buildRoot, library));
       _libraries[library] = libraryTemp;
       items.add(new JS.ExportDeclaration(
           js.call('const # = Object.create(null)', [libraryTemp])));
 
       // dart:_runtime has a magic module that holds extenstion method symbols.
       // TODO(jmesserly): find a cleaner design for this.
       if (_isDartRuntime(library)) {
         items.add(new JS.ExportDeclaration(
             js.call('const # = Object.create(null)', [_dartxVar])));
       }
@@ skipping 3549 matching lines @@
   bool _externalOrNative(node) =>
       node.externalKeyword != null || _functionBody(node) is NativeFunctionBody;
 
   FunctionBody _functionBody(node) =>
       node is FunctionDeclaration ? node.functionExpression.body : node.body;
 
   /// Returns the canonical name to refer to the Dart library.
   JS.Identifier emitLibraryName(LibraryElement library) {
     // It's either one of the libraries in this module, or it's an import.
     return _libraries[library] ??
-        _imports.putIfAbsent(
-            library, () => new JS.TemporaryId(jsLibraryName(library)));
+        _imports.putIfAbsent(library,
+            () => new JS.TemporaryId(jsLibraryName(_buildRoot, library)));
   }
 
   JS.Node annotate(JS.Node node, AstNode original, [Element element]) {
     if (options.closure && element != null) {
       node = node.withClosureAnnotation(closureAnnotationFor(
           node, original, element, namedArgumentTemp.name));
     }
     return node..sourceInformation = original;
   }
 
@@ skipping 55 matching lines @@
       // TODO(leafp): The above only handles the case where the return type
       // is exactly Future/Stream/Iterable.  Handle the subtype case.
       return DynamicTypeImpl.instance;
     }
   }
 }
 
 /// Choose a canonical name from the library element.
 /// This never uses the library's name (the identifier in the `library`
 /// declaration) as it doesn't have any meaningful rules enforced.
-String jsLibraryName(LibraryElement library) {
-  return pathToJSIdentifier(library.source.uri.pathSegments.last);
+String jsLibraryName(String buildRoot, LibraryElement library) {
+  var uri = library.source.uri;
+  if (uri.scheme == 'dart') {
+    return uri.path;
+  }
+  // TODO(vsm): This is not necessarily unique if '__' appears in a file name.
+  var separator = '__';
+  String qualifiedPath;
+  if (uri.scheme == 'package') {
+    // Strip the package name.
+    // TODO(vsm): This is not unique if an escaped '/'appears in a filename.
+    // E.g., "foo/bar.dart" and "foo$47bar.dart" would collide.
+    qualifiedPath = uri.pathSegments.skip(1).join(separator);
+  } else if (uri.path.startsWith(buildRoot)) {

[Paul Berry, 2016/04/28 15:49:30]

This won't be correct on Windows, because uri.path uses forward slashes, but
buildRoot uses backslashes.  Use uri.toFilePath() here and on line 3861.

+    qualifiedPath =
+        uri.path.substring(buildRoot.length).replaceAll('/', separator);

[Paul Berry, 2016/04/28 15:49:30]

Use path.separator instead of '/'.

+  } else {
+    // We don't have a unique name.
+    throw 'Invalid build root.  $buildRoot does not contain ${uri.path}';

[Siggi Cherem (dart-lang), 2016/04/28 15:13:28]

nit: maybe rephrase as "Invalid build root. ${uri.path} does not start with
$buildRoot."? (technically it's uri.path that should contain build-root, instead
of the other way around)

[vsm, 2016/04/28 15:31:45]

I was thinking "contain" in the directory sense not the string sense.  Maybe I
could word that better?

[Siggi Cherem (dart-lang), 2016/04/28 15:43:49]

Ah! :) makes sense. maybe: "is not a parent of"?

+  }
+  return pathToJSIdentifier(qualifiedPath);
 }
 
 /// Shorthand for identifier-like property names.
 /// For now, we emit them as strings and the printer restores them to
 /// identifiers if it can.
 // TODO(jmesserly): avoid the round tripping through quoted form.
 JS.LiteralString _propertyName(String name) => js.string(name, "'");
 
 // TODO(jacobr): we would like to do something like the following
 // but we don't have summary support yet.
@@ skipping 13 matching lines @@
 }
 
 bool isLibraryPrefix(Expression node) =>
     node is SimpleIdentifier && node.staticElement is PrefixElement;
 
 LibraryElement _getLibrary(AnalysisContext c, String uri) =>
     c.computeLibraryElement(c.sourceFactory.forUri(uri));
 
 bool _isDartRuntime(LibraryElement l) =>
     l.isInSdk && l.source.uri.toString() == 'dart:_runtime';